By Gerrit van Leeuwen

Feyenoord have reached an agreement to sign goalkeeper Kenneth Vermeer from arch rivals Ajax on a four-year-deal.

The 28-year-old, who progressed through Ajax’s famed youth system before making his first-team debut in 2005, has fallen down the pecking order in Amsterdam following the emergence of Jasper Cillessen.

The deal taking Vermeer to Ajax’s bitter Eredivisie rivals is for a fee reported to be in the region of £600,000.

Ajax have already moved to replace him with the signing of Diederik Boer, 32, from PEC Zwolle.

A statement on Ajax's official website read: "Ajax and Feyenoord have agreed on the transfer of Kenneth Vermeer.

"The move to the Rotterdam club is available immediately. The keeper was under contract with Ajax until June 30, 2015."

Ajax boss Frank de Boer told Fox Sports: "You grant everyone all the best. Kenneth is one of the best goalkeepers in the Netherlands, along with Jasper Cillessen.

"Feyenoord is therefore stronger and that can’t be the intention. You do not have to make your competitor stronger."

The signing of Vermeer will see Feyenoord goalkeeper Werner Hahn, who only joined on a free transfer from FC Dordrecht this summer, move to feeder club Excelsior on a season-long loan.